Fender Vintage Reissue '59 Bassman vs Peavey Classic 50

I have a Peavey Classic 50 4 x10. I been proposed a deal through CL that will net me a Fender Vintage Reissue '59 Bassman. Though this is more expensive than my Peavey, is it any better or different. They have similar stats. Before you say try it out, he's a long drive away. No, I don't have time in the next couple of days to go to music stores looking for one. Any helpful info will be accepted gladly.

The Peavey has two inputs, bright and normal. It has two channels, one clean, one dirty. The dirty channel obviously has a pre-amp vol control, but it also has a post preamp vol, and a master volume. The Peavey also has an FX loop and reverb. It runs 4 x EL84 valves in cathode biased Class A push pull. It's got a solid state rectifier.

The Bassman is different. It has two channels, one normal, one high sensitivity. It has two inputs for each channel, normal and bright. It has a volume for each channel. There is no master volume: it does not produce a dirty sound by itself until you turn it up. The EQ is the same as the Peavey: bass, mid, treb, presence. It has no reverb or loop. It runs two 6L6 valves in fixed bias Class AB push pull, with a valve rectifier. It is built with solid pine and covered with real tweed.

The Bassman is a good sounding amp. It takes pedals beautifully. Much better than the Peavey. But it does not produce an overdriven sound at low volumes without a pedal or attenuator. The dirty channel on the Peavey is very good, with a nice British voicing to it. The overdrive of the Fender Bassman is coarser and richer, and in my view better. But it's loud. To hear it you have to turn up to the volume required to stay with a drummer. It is not simple to hook up an attenutator to the Bassman, but it can be done. You need to have a junction box to bring the four RCA jacks for the speakers together into a single 2 Ohm jack, into which you can plug your attenuator. I have done this. BB has had it done on his, too. No mod to the amp is required, and it's not a big job. But you should know up front.

The Bassman is a superb working amp. It is less good as a practice / noodling in the house amp. I use mine in a three piece working band. I run it at about 40-50% volume, with a baffle in front. I use the baffle on all my amps to kill the treble and spread the sound sideways and up, and it also reduces apparent volume, which is very cool. I don't need an attenutator. I hooked up my attenuator on Monday night for the first time in a long time, and ran it for one song (Sister Luck) at -4 dB, and it was too quiet. It was gone one a minute later and we were back to the plain old naked amp.

At those volume settings, with a good 12AX7 valve in V1, 5881 power valves (6L6WGB) and a Les Paul with vintage style humbuckers, it provides enough overdrive to play Black Crowes, Rolling Stones, Zeppelin, AC/DC, with no pedals switched on. It responds beautifully to distortion, O/D or distortion pedals. Because it's non-master volume, it is far more touch sensitive and responsive to changes in vol control at the guitar than the Peavey.

It's a very dynamic and aggressive sounding amp when driven, and very sweet when clean. You can get great sounds out of it at low volumes, but you must use pedals to do so and you'd not be using the amp to best effect.

The 5881 valves are important to its sound. The 5881 - or 6L6WGB - is a lower powered valve than the more common 6L6GC. The 5881 is 18-23 Watts, while the 6L6GC is 30 Watts. What this means in practice is that if you run 5881s in the Bassman (which is what they came with in the 1950s), it'll have less clean head room and go into overdrive at lower volumes. About 40% power. If you use 6L6GCs, you'll have to turn it up to 50% power to start getting overdrive.

New Sensor offers a re-issue Tung Sol 5881 made in Russia which sounds pretty good. That would be the one to go for.

But if you're only noodling in your room, the Peavey might be the better amp.

Splattle101, I learn stuff from your posts all the time. Just dropped in 'cause I like Bassmans and hope to have one, someday, and look at all this information. I'm going to try to post a tube question soon, keep an eye out for it, will you please?

Would that reissue be wired point-to-point? I started with an old Peavey 4x10 somethingoranother, it was covered with tweed and I couldn't make it sound good no matter what I tried - but that was with an old Ibanez, the one that was a copy of the Alembics, with a terrible active circuit. If you've got a good sounding guitar, it might be fine to stay with that - but I vote for the trade. Just can't beat a good Bassman - it's the circuit that is at the heart of everything else.

The '59 Bassman LTD that I have is NOT hand wired. It's got a printed circuit board. However, the pots, jacks and valve bases are all mounted on the chassis, not on the PCB. This is a very good thing. I am not highly enamoured of the components Fender have used in this thing. It's got horrid little Illinois Capacitor electrolytics for the filter caps. There are some others in there (presumably coupling caps and tone caps) that could either be either very small polypropylenes or ceramics. I understand from some reading I've done that the transformers are pretty good. I plan to replace the guts of mine with a hand-wired board one day. This is not as simple as it sounds, though, because the old originals had a separate tray for the big old filter caps. The RI doesn't need a tray because it uses these yucky little IC caps, and so there's no cut out in the chassis to accommodate the tray. I haven't yet sat down and worked out if decent filter caps will fit inside the existing chassis with a hand-wired board, or whether I have to do some cutting.

Also, the speakers can be a bit flaky. They're new-manufacture Jensen P10Rs, nominally 25 Watts at 8 ohms. I have had three out of eight of them crap out on me with cone fractures, coil rubbing, general farting noises. Nice sounding, but fragile. If you're in the US it's probably economical to replace them with Webers or something. But beware, the power tranny sits right on the magnet of the upper left hand speaker when viewed from the back. You won't fit a speaker with a ceramic magnet in there.

I don&#8217;t know if there&#8217;s isn&#8217;t some confusion here. The early 90s reissue of the Bassman, the first reissue, was a different beastie. It had a solid state rectifier and speakers with ceramic magnets.

The more recent reissues have a valve rectifier and have Jensen P10R speakers. The P10R has AlNiCo magnets and is made in Italy. It is blue.

I don&#8217;t know if there&#8217;s isn&#8217;t some confusion here. The early 90s reissue of the Bassman, the first reissue, was a different beastie. It had a solid state rectifier and speakers with ceramic magnets.

The more recent reissues have a valve rectifier and have Jensen P10R speakers. The P10R has AlNiCo magnets and is made in Italy. It is blue.

I don&#8217;t know if there&#8217;s isn&#8217;t some confusion here. The early 90s reissue of the Bassman, the first reissue, was a different beastie. It had a solid state rectifier and speakers with ceramic magnets.

The more recent reissues have a valve rectifier and have Jensen P10R speakers. The P10R has AlNiCo magnets and is made in Italy. It is blue.

Click to expand...

The earlier versions of the Fender bassman had two options pull out the solid state recifier and replace it with a tube and that takes about one minute to do so and the version Im referring to did not have P10r speakers as well. No verification numbers on the rims they were Eminence not Jensen with different cones .

The early Bassman re-issues from the early 90s had to be modified to have a valve rectifier. There's discussion of this mod and what's required over at the Fender forum. They've got a sub-fourm in their amp sub-forum talking specifically about the Bassman.

I know the speakers were ceramic magnet because a mate of mine bought two of the earliest re-issues in 1991. I saw them. I remember the complications he had to negotiate in replacing them.

Regarding the Eminence speakers, I have one of those in my Bassman. It's a warranty replacement for one of the Jensen's that shat itself. It's an OK speaker, but it's not the same as the ceramic magnet speakers from the early ones.

It'd be interesting to work out a history of the re-issues. They've been through a few changes since 1990 and they've now got 19 years of history, which is longer by far than the original production run of tweed Bassmans.

I forget which year mine was ,but it the 3rd one to land in Canada 2nd to hit Toronto. It had the pull out ss rect. in a tube socket, and 4 alnico (blue) eminence and a leather handle.
I don't remember it sounding any better than todays offering. Which is nicer looking and come with better PR tubes and a tube rect.

If I remember right the serial# was 0450 don't know what that indicates?
Russ they did come with ceramic ? did not know that.!

The other difference between the older Bassman RI and the current Bassman LTD is the pot for adjusting bias. The RI (like the original) doesn't have it. I don't think it's a huge mod to put one in, but it's not stock.

The early version Fender bassman had a leather handle correct and the blue alnico speakers also a Kapton voice coil and a lapped paper cone .

The solid state recifier had a tube socket end which was easily pulled out and replaced with a tube used which gave it more sag and less power .

Here is some information I have and would like to pass along about the earlier reissue bassman .

Mod your Bassman reissue for vintage tone

To start I´m sorry to point out that this here will NOT turn your Bassman
reissue amp into an original, it´s NOT a 1:1 copy and it is NOT exactly
sounding like the old, most sought after 5F6A Bassman version with the
4x10" speaker open cabinet. But that´s ok, the reissue amp is a fantastic
sounding guitar amp, in some cases even better than the original. All this
mods here will take you VERY close to the famous vintage Bassman sound
and it is divided into three levels. Keep in mind that this works for the first
reissue product line from Fender. I have never seen the "new" reissue
Bassman amp from Fender, called the "Bassman LTD" from inside, so
maybe they are somewhat different.

1st level (almost no work)

Slightly less volume, more warmth:

Remove the solid-state rectifier with a tube-rectifier, eg. GZ34 or 5U4G.
Play through the normal channel and you´ll find that power output is
reduced to about 40 watts, so you can get the same tones at slightly
lower volumes. In addition, the highs smooth out, ovrall
warmth/ambience/organic vibe increases, and the amp becomes more
tonally reponsive to the way you attack your instrument.

Even less volume, sweet vintage tone:

Remove the first 12AX7 preamp tube (first socket from the right when
looking in the amp from backwards) and replace it with a 12AY7. What
you get is much less gain AND (if you can believe it), the amp gets even
warmer and fuller.

Now try this fat, bluesy distortion:

Plug your guitar into input #1 of the NORMAL channel and run a shielded
cable from input #2 of the NORMAL channel to input #1 or #2 of the
BRIGHT channel. Start with the NORMAL volume on 4 and the BRIGHT
volume on 9 and experiment from there. This suggested setting produces
a rich, vibrant distortion at a slightly lower volume.

Bonus: Even if you use just one channel, the two volume controls interact.
Try plugging your guitar into the NORMAL channel, set it up the way you
normally do, then listen to how the sound changes as you rotate the
BRIGHT channel volume knob.

2nd level (requires some work)

Cabinet modding:

The reissue cabinet is not made out of pine wood like the original. If you
want, you can build a new one out of massive pine but I don´t think this
is necessary. I only replaced the baffleboard for pine wood one and it
sounds great. There are some additional optical mods you can do, to
make your reissue look like an old tweed Bassman. I painted mine several
times with a nitro laquer and added some brownish dye to make it look
like a mixture of an old nitro paint, dust, dirt and nicotine. It works great
and looks really cool. To do some more aging you can remove the socalled
"oxblood grille cloth" from the baffleboard, put it into a bucket and cover it
for some days with black coffee or tea. This will give it the look of 40
years and rough use on stage. You can also put all the metal parts, screws
etc. from the cabinet into another bucket and cover it for some days with
any coke, the brand doesn´t matter - I used Pepsi Coke and it worked fine
;-) After reassembling your cabinet, make sure to fasten everything firmly
so that nothing can rattle and shake, this will also help you to enhance the
sound of the amp. Take special care for the screws that are holding the
speakers !!!

Tube modding:

Modern tubes are sounding different from old ones, that´s a fact. So try to
find NOS tubes for your amp, to give it more of the real tone. Don´t use
the original Tungsol or Philips 5881, they can only handle up to approx.
400 volts and our reisuue Bassman produces 450 volts !!!! I have good
results with military surplus NOS tubes from GE, I use a GZ34, a 12AY7
and two 12AX7 and stronger Phillips 5881 that can handle the power. It
will require some time and money to find all this parts but it´s worth the
effort.

Technical spruce-up

It is a good idea to replace all the jacks with high-quality Neutrik or even
better Switchcraft jacks, the original ones are a little bit weak and of poor
quality. While you are doing this I recommend to replace all the cables
coming from them for a high quality cable, the stock stuff is a very cheap
and weak wire. I also recommend to completely rewire the speakers and
to solder the speaker cables directly to the lugs of the speakers, the stock
connectors gave me some trouble !!! I used a high quality much thicker
speaker cable for that and soldered them to only one 6.3 mm standard
plug. I also replaced the RCA connectors (amp output to the speakers) in
the amp with a single mono jack. That´s not original but it gives you the
freedom to use an attenuator or DI box without any hazzle ..... or have
you ever seen such a unit with RCA input jacks ?!? ;-)

3rd level (requires a lot of work, tools and skills)

This is the point where you will need the circuit wirings of both amps, the
reissue and the original old one. If you haven´t download it yet, this is the
point to do so and print it.
All the work now is highly technical and requires good skills in basic
electronics and how to solder on PCB´s. There are a lot of parts inside the
reissue, that are different or simply not existing compared to the original
amp. Again, don´t do this if you don´t know what you are doing !!!!!

Modding the power supply system (wrote by Hoffman Amplifiers)

The original 5F6A bassman power supply

Stage one: The old 5F6A Bassman circuit has a total of four stages of
power supply filtration. There are five capacitors total, but two caps are
joined together in parallel and count as one stage and this is stage one.
Parallel means that the two positives are joined together and the two
negatives are joined together. This gives you 40uf total capacitance in
stage one of the power supply. Stage one is right off the rectifier tube/pin
8 and is the first stop for the power supply voltage on the circuit board.

Stage two: From stage one, the power supply voltage travels through the
choke. On the other side of the choke is stage two and there is another
20uf/500v cap connected to this stage. The 470 ohm screen grid resistors
are connected to this stage and feed pin four of each power tube.

Stage three: The power supply voltage then goes through a 4.7k power
supply resistor and ends up at stage three. This is the voltage supply for
the phase inverter tube and there will be a 20uf/500v cap connected to
this stage also. You will see a 82k and 100k resistor connected to this
stage. These two resistors head towards the phase inverter tube and
supply the plates, pins 1 and 6 with voltage.

Stage four: The power supply voltage then goes through a 10k power
supply resistor and stops at the last stage, stage four. There will be a
20uf/500v cap connected to this stage also. Sometimes there is a smaller
value on this stage but a 20uf/500v cap works great. There are three
100k plate load resistors connected here that feed the plates of the two
pre-amp tubes.

That is all four stages of the power supply, look at one of my 5F6A layout
diagrams to see this system presented in a simple linear fashion. I have
small numbers on the layout diagram next to each power supply stage to
show where stages 1,2,3 and 4 are located on my board kit.

Now we go onto the Bassman re-issue and the differences in the power
supply.

The reissue 5F6A bassman power supply:

Stage one and two: Bassman reissue
Stage one: Stage one and two are in the capacitor can on the back of the
chassis in the Bassman reissue. This can has four caps inside but there
are only two stages of power supply filtration in this can. You will see two
100uf/350v caps (stage one) that are joined together in Series, not
parallel and two 47uf/350v caps (stage two) joined together in series.
When you put two caps together in series, the capacitance is divided by
two, and the voltage is added together. If you picture two caps stacked up
like two flashlight batteries so that the positive of the bottom cap is
connected to the negative of the top cap, that is series. You use the
negative of the bottom cap and the positive of the top cap for the
electrical connections.

So we have stage one, which is two 100uf caps, divided by two = 50uf of
total capacitance and a voltage rating of 350v + 350v = 700volts. Stage
one has a red wired soldered to the pc board. The red wire is connected to
the positive end of the top 100uf/350v cap in the series stack. The red
wire then goes through a hole in the chassis and ends up inside the amp
connected to stage one on the circuit board.

Stage two: We also have stage two in this can which is the two
47uf/350v caps in series, divided by two = 23.5uf with a total voltage
rating of 700 volts. Stage two has an orange wire soldered to the pc
board. The orange wire is connected to the positive end of the top
47uf/350v cap in the series stack. The orange wire then goes through a

hole in the chassis and ends up inside the amp connected to stage two on
the circuit board.

Both of these series arrangements for stage one and two have 220k
bleeder resistors across the leads of each cap to balance the voltage and
bleed down the voltage after the amp has been shut down. Leave all of
this arrangement in the cap can alone, it is perfectly useable and just fine
as a far as power supply filtration goes.

There are a couple changes that I like to do to the wires leaving the filter
cap pc board. I like to run new stranded 18 gauge wires in place of the
stock red, orange and black wires that leave this board. You could use the
existing red and orange wires if they will reach the lugs on the board
where they need to be connected. They are a little stiff and hard to work
with, but they will work.

The black ground wires are not long enough to reach the power
transformer grounding point and it is a good idea to run your grounds like
I have explained below.

New black ground wires: Unscrew the four screws holding this pc board
in place and turn it upside down so you can work on it. Make sure you
have drained the capacitors first by touching the red and orange wires to
the black wires. If you touch all four wires together for 30 seconds, you
will be safe and the caps will have bled down enough so as not to shock
you.

You are going to need one piece of black 18ga stranded wire that is long
enough to go from the cap can pc board, through the hole in the chassis
and end up over by the power transformer. This wire will be grounded on
the same power transformer bolt as the other major grounds in the amp.

Find the spot where the two black wires are joined to the cap can pc board
and remove the two black wires. Take your piece of black 18ga stranded
wire and strip enough of the end of the wire so that you can bridge across
the gap and connect the wire end to both places on the pc board where
the old black wires were. You can just solder the wire flush to the surface
of the copper pc board traces. You may have to scrape the copper clean to
get a good solder connection. You do not have to stuff the new black wire
into a hole, just laying it on the copper surface and soldering it to the
surface will work just fine. Ok, now you should have just one black wire
that is connected to both grounds on the cap can pc board. The other end
of this black wire gets a ring terminal crimped and soldered to it. It is
bolted down to the chassis on the same power transformer bolt as the
power cord green wire, the black wire from the end of the board kit and
the red/yellow center tap wire from the power transformer.

These are the major grounds of the amp and it is a good idea to put a
soldered ring terminal on all the wires and use one of the power

transformer bolts to make a good chassis/ground connection. Do not try
to solder wires to a chassis, always crimp and solder a ring terminal and
bolt down your major grounds.

So basically you just replaced two separate ground wires with one big
one. Stage one and two will share a common ground wire. This method
has been tried and tested and makes for a very quiet amplifier, please do
not try and re-invent the wheel here.

While I am on the subject of grounds, do not try any of that star ground
crap that some techs preach. The star grounds create more problems than
they fix. This method I am describing here has been proven to produce a
very quiet amplifier as far as ground hum is concerned.

Now that we have our grounds for stage one and two taken care of we
need to take care of the two positive wires for stage one and stage two. I
replace both the red and orange wires with a new piece of stranded 18ga
red wire. If you are using the old red and orange wire, you can skip this
section and go to Stage three and four.

New red and orange positive wires: You will be replacing the red and
orange wires with two red 18ga stranded wires. You will need to figure out
how long each piece of red 18ga stranded wire should be and then solder
them in place of the red and orange wires. The red wire is stage one and
the orange wire is stage two of the power supply filtration. The red wire is
connected to the positive end of the two 100uf caps and the orange wire
is connected to the positive end of the two 47uf caps. Look at the layout
diagram and find the turret lugs for stage one and two and solder the
wires to the correct spot. Flip the cap can pc board over and bolt it down
to the chassis. Put the cover back on and screw it down. You have just
finished stage one and two of the power supply filtration circuit.

Stage three and four: Stage three and four filter caps are on the main
pc board in the Bassman reissue. There should only be two 22uf/500v
caps on that board, but there are 3 for some unknown reason. We only
need two more caps for stage three and four and you can do one of two
things here. You can remove two of the 22uf/500v caps from the main pc
board and reuse them or you can use two new caps. I reuse two of the
original caps, but the leads are kind of short. New caps are nicer because
you have longer leads, but the old caps work just fine unless they are 15
years old. Get new caps if the caps are really old.

The best way that I have found to mount stage three and four caps is this.
Your main board kit circuit board should already be installed and all the
wires in the amp should be installed except the wires that lead to the
pots. Install the pot harness, but do not install the pot wires yet. Take the
two 22uf/500v caps and make a little hook at the very end of the negative
wire. This hook will hook onto the pot harness ground buss wire that runs
down the back of the pots.

Put the two 22uf/500v caps down inside the amp, underneath the pot
harness so that they are parallel to the front pot panel and as close to the
front metal panel as is possible. Make sure the caps are not near the high
voltage power supply rail that runs down the front of the circuit board.
The caps are sitting on the blank area of the circuit board, towards the
pots side of the chassis. If you move the caps around, you will find a spot
that lets you connect the positive ends to the correct lugs on the circuit
board and the negative ends will be facing each other. In other words, the
positive ends are far apart from each other and both caps are in a straight
line like a couple flashlight batteries.

Face the two negative cap ends towards each other and wrap the hook
onto the pot ground buss wire. Solder the negative ends in place. I like to
take a piece of the PVC coating off the red 18ga wire and slide it onto the
positive ends of each 22uf/500v cap. This lets you know that the wire is
hot and to keep your fingers away and keeps you from accidentally
touching the positive end of the cap. Make a small hook on the positive
end of each cap and solder each cap to stage three and stage four on the
circuit board.

You will notice that stage three and four each have several lugs that the
22uf/500v caps can be soldered to, you do not have to solder it to the lug
that you see on the layout diagram. If three lugs are all connected in a
row with a piece of buss wire, then any of those lugs will work. That is
called a buss and you can figure out which lugs work best for the stage
three and four capacitors.

Stage three and four capacitors do not have very long leads and this is a
good thing. The ground noise level is very low after doing the capacitors
and grounds the way I have described.

One last ground tip: The ground wire coming from the preamp end of
the board kit should be soldered to the pot buss wire or to a input jack
ground tab. If you use an input jack for the grounding connection, make
sure the jack is making good contact with the chassis. I prefer to solder
this ground wire to the pot buss harness wire. Again, do not do any star
grounds; you will have problems and ground noise. I have removed many
star grounds on amps over the years because people were told "This is
great, you must do it". There is more resistance in a piece of wire than
there is in a good chassis ground. Chassis grounds have always worked
well if done properly. Look how many millions of amps were built that way
and work just fine. The only reason you see some Fenders having
problems is because the brass ground plate under the pots corrodes and is
not making good contact with the chassis. I prefer not to use the brass
plates and do it like Marshall did it, solder a buss wire down the back of
the pots and let all the pots make a ground connection to the chassis. The
ground currents make their way through the chassis and back to the main
grounding point at the power transformer. You should have four ground
wires connected to ground through a bolt on the power transformer. The

power cord green wire, the black wire from the end of the board kit, the
red/yellow center tap wire from the power transformer and the black wire
from the filter cap can.

Parts tuning

+ Desolder and remove C25 if it´s populated in your amp
+ Desolder and remove C21
+ R28 (82 kOhm): solder an additional 100k resistor in parallel
+ R41 (46 kOhm): solder an additional 150k resistor in parallel
The most important reasons why the reissue is not a 1:1 copy

1. The original is point-to-point wired
2. The original has a different layout
3. The original uses different parts (carbon comp resistors, mica caps,
Astron caps ......)
4. The reissue uses a higher current of approx. 450 volts, the original only
400 volts. So the reissue is louder and more dynamical but also harder
and brighter
5. The original uses a TRIAD transformer that sounds completely different
from the reissues transformer. There is a good copy available from
Mercury Magnetics (USA)
6. The old Bassman uses Tungsol or Phillips 5881 tubes but they can only
handle 400 volts (look at No. 4 !)
7. The original uses a cabinet out of massive pine wood, the reissue
cabinet is made out of plywood, so it sounds harder and without some of
the vibe.
8. The speakers are sounding completely different from the original
Jensen speakers. You can buy good copies from Weber VST
So you see it´s not that easy to make the reissue a real 1:1 copy of the
original but it´s still possible ! If you want to take your time and spend a
lot of money you can buy almost original parts to convert the reissue into
the real thing. you can buy the following things:

I haven't read that all the way through in detail, but what he describes of the filter caps in the RI is quite different to the LTD. For a start, there's no 'can' in the LTD. The filter caps are all relatively small electrolytics from Illinois Capacitor, and they're all mounted inside the main chassis, next to the main PCB. There is no 'can' (or tray, as on the originals).

I had a look last night at the schematic for my '59 Bassman LTD and compared it to the schematic for the vintage 5F6A. So far, I've only covered from the input to the end of the tone stack, but what I've seen so far is:

1. the preamp circuits are identical.
2. the preamp valve in the vintage was 12AY7 instead of the modern 12AX7. I've discussed the effect of swapping that valve elsewhere.
3. the volume pots on the LTD are linear, and audio taper on the vintage.
4. the tone stack circuits are identical, and the pots are the same value and type, except:
5. the tone cap for the bass control is 0.1 uF in the LTD, and 0.022 uF in the vintage. This is interesting, because it means the difference between the mid and bass controls on the vintage tonestack was the difference betwee the pots.
6. the presence pot is 25 k in the LTD and 5 k in the vintage.

The other thing that is different at a glance, but that I've not looked into in any detail yet, is that the B+ voltage for the LTD is 475 V (I think), and 432 V for the vintage. Which is interesting because the data sheet for the 5881 valve gives a max plate voltage of 400 V. I know these maximums are honoured more in the breach than the observance, but this looks to me as if the original amp was already operating a little hot for the 5881. The higher plate voltage would tend to make the amp brighter, but the larger bass cap would tend to make it darker...